360 heads on 318

Depends what you want.
With stock CR and a 270 ish cam the stock 318 heads will get you about 300 hp. So if you want more you could go more cam but you don't have the CR to support that or more head flow the best way would be by porting but not everyone is confident not doing that or by swapping on better heads.
Ported 318 heads is a win tie situation, gain cfm break even on cr. 360 is a win lose situation gain hp on cfm and lose hp on cr.
The best swap would be magnum head win win gain both cr and cfm.

Saying that before I knew about the CR situation I've and people I know have done the 360 head swap and have made power.